In a photolithography process, ArF(193 nm) excimer laser of short wavelength is used as the exposure light source in order to improve the marginal resolution of the photoresist pattern. However, if the wavelength of the exposure light shortens, optical interference effect by the light reflected from the etching layer of the semi-conductor substrate increases, and the pattern profile or the uniformity of thickness is deteriorated due to undercutting, notching, and so on. To overcome these problems, a bottom anti-reflective coating layer (bottom anti-reflective coatings: BARCs) is conventionally formed between the etching layer and the photoresist layer to absorb the exposure light (reflected light). The bottom anti-reflective coating layer can be classified according to used materials into the inorganic anti-reflective coating layer made of titanium, titanium dioxide, titanium nitride, chrome oxide, carbon, amorphous silicon, and so on, and the organic anti-reflective coating layer made of a polymer material. Conventionally, in comparison with the inorganic anti-reflective coating layer, the organic anti-reflective coating layer does not require complex and expensive apparatus such as a vacuum evaporator, a chemical vapor deposition (CVD) device, a sputter device and so on for forming the layer, and has a high absorptivity of a radioactive light, and low molecular weight materials does not diffuse from the organic anti-reflective coating layer into a photoresist layer during a heating, coating, and drying process, and the organic anti-reflective coating layer has an excellent etch rate in a dry etch process of a photolithography process.
FIG. 1 is a drawing for showing a method of generally forming the photoresist pattern. As shown in FIG. 1, the conventional method for forming the photoresist pattern can be roughly classified into a positive tone development (PTD) and a negative tone development (NTD). The PTD is a method of forming patterns by selectively dissolving and removing an exposed region of a photoresist film with a positive tone developer, and the NTD is a method for forming patterns by selectively dissolving and removing a non-exposed region of a photoresist film with a negative tone developer. Development of a fine pattern formation process using next-generation EUV (Extreme ultraviolet lithography), DSA (Diffusion Self Align), etc. has been delayed. The NTD enables the formation of fine patterns in comparison with the PTD by changing the alkaline developer to an organic developer using a current exposure equipment so that it is advantageous that additional equipment is not necessary.
Korean Unexamined Patent Publication No. 10-2011-0028763 discloses an isocyanurate compound for forming an organic anti-reflective coating layer represented by the following Formula 1 and a composition containing the same.

In Formula 1, R is independently a hydrogen atom or a methyl group, R1 is independently a chain or cyclic saturated or unsaturated hydrocarbyl group of 1 to 15 carbon atoms containing 0 to 6 of hetero atoms, and R2 is a chain or cyclic saturated or unsaturated hydrocarbyl group of 1 to 15 carbon atoms containing 0 to 15 hetero atoms.
The isocyanurate compound is excellent in stability and etching rate at high-temperature and has a high refractive index. When the isocyanurate compound is used in the PTD, the reflectivity is controlled and the pattern profile is corrected to form a vertical pattern so that the process margin is improved. On the other hand, when the isocyanurate compound is used in the NTD. The under-cut occurs at the photoresist bottom (PR bottom) portion, furthermore when it is severe, tunneling occurs, and the adhesion to the photoresist is poor so that the process margin is insufficient. It is required a study of a composition for forming an organic anti-reflective coating layer which controls the reflectivity by maintaining a high refractive index which is required in an immersion process, has high etch rate and excellent adhesion to the photoresist and can improve the process margin.